需要一种在 Python 中加载嵌入、转义的 JSON 字符串的方法

Question

我必须解析以下 JSON 字符串：

{"JobDescription":"{\"project\": \"1322\", \"vault\": \"qa-122\"}"}'

如果我尝试使用 json.loads，我会得到以下信息：

>>> import json
>>> print json.loads('{"JobDescription":"{\"project\": \"1322\", \"vault\": \"qa-122\"}"}')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/json/__init__.py", line 338, in loads
    return _default_decoder.decode(s)
 File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/json/decoder.py", line 365, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
 File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/json/decoder.py", line 381, in raw_decode
    obj, end = self.scan_once(s, idx)
ValueError: Expecting , delimiter: line 1 column 22 (char 21)

我无法控制我收到的由另一个系统生成的字符串。

Answer 1

您没有生成嵌入的反斜杠；Python 将 解释\"为转义引号，最终字符串仅包含引号：

>>> '{"JobDescription":"{\"project\": \"1322\", \"vault\": \"qa-122\"}"}'
'{"JobDescription":"{"project": "1322", "vault": "qa-122"}"}'

使用原始字符串或双斜杠：

>>> r'{"JobDescription":"{\"project\": \"1322\", \"vault\": \"qa-122\"}"}'
'{"JobDescription":"{\\"project\\": \\"1322\\", \\"vault\\": \\"qa-122\\"}"}'
>>> '{"JobDescription":"{\\"project\\": \\"1322\\", \\"vault\\": \\"qa-122\\"}"}'
'{"JobDescription":"{\\"project\\": \\"1322\\", \\"vault\\": \\"qa-122\\"}"}'

然后加载正常：

>>> import json
>>> json.loads('{"JobDescription":"{\\"project\\": \\"1322\\", \\"vault\\": \\"qa-122\\"}"}')
{'JobDescription': '{"project": "1322", "vault": "qa-122"}'}

您可以从那里解码嵌套的 JSON 文档：

>>> decoded = json.loads('{"JobDescription":"{\\"project\\": \\"1322\\", \\"vault\\": \\"qa-122\\"}"}')
>>> json.loads(decoded['JobDescription'])
{'project': '1322', 'vault': 'qa-122'}